diff options
Diffstat (limited to 'xmpp-vala/src/module/xep/0027_pgp/module.vala')
| -rw-r--r-- | xmpp-vala/src/module/xep/0027_pgp/module.vala | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/xmpp-vala/src/module/xep/0027_pgp/module.vala b/xmpp-vala/src/module/xep/0027_pgp/module.vala new file mode 100644 index 00000000..fee6b9e4 --- /dev/null +++ b/xmpp-vala/src/module/xep/0027_pgp/module.vala @@ -0,0 +1,206 @@ +using GPG; + +using Xmpp.Core; + +namespace Xmpp.Xep.Pgp { + private const string NS_URI = "jabber:x"; + private const string NS_URI_ENCRYPTED = NS_URI + ":encrypted"; + private const string NS_URI_SIGNED = NS_URI + ":signed"; + + public class Module : XmppStreamModule { + public const string ID = "0027_current_pgp_usage"; + + public signal void received_jid_key_id(XmppStream stream, string jid, string key_id); + + private static Object mutex = new Object(); + + private string? signed_status; + private string? own_key_id; + + public Module() { + GPG.check_version(); + signed_status = gpg_sign(""); + if (signed_status != null) own_key_id = gpg_verify(signed_status, ""); + } + + public bool encrypt(Message.Stanza message, string key_id) { + string? enc_body = gpg_encrypt(message.body, new string[] {key_id, own_key_id}); + if (enc_body != null) { + message.stanza.put_node(new StanzaNode.build("x", NS_URI_ENCRYPTED).add_self_xmlns().put_node(new StanzaNode.text(enc_body))); + message.body = "[This message is OpenPGP encrypted (see XEP-0027)]"; + return true; + } + return false; + } + + public string? get_cyphertext(Message.Stanza message) { + StanzaNode? x_node = message.stanza.get_subnode("x", NS_URI_ENCRYPTED); + return x_node == null ? null : x_node.get_string_content(); + } + + public override void attach(XmppStream stream) { + Presence.Module.require(stream); + Presence.Module.get_module(stream).received_presence.connect(on_received_presence); + Presence.Module.get_module(stream).pre_send_presence_stanza.connect(on_pre_send_presence_stanza); + Message.Module.require(stream); + Message.Module.get_module(stream).pre_received_message.connect(on_pre_received_message); + stream.add_flag(new Flag()); + } + + public override void detach(XmppStream stream) { + Presence.Module.get_module(stream).received_presence.disconnect(on_received_presence); + Presence.Module.get_module(stream).pre_send_presence_stanza.disconnect(on_pre_send_presence_stanza); + Message.Module.get_module(stream).pre_received_message.disconnect(on_pre_received_message); + } + + public static Module? get_module(XmppStream stream) { + return (Module?) stream.get_module(NS_URI, ID); + } + + public static void require(XmppStream stream) { + if (get_module(stream) == null) stream.add_module(new Module()); + } + + public override string get_ns() { return NS_URI; } + public override string get_id() { return ID; } + + private void on_received_presence(XmppStream stream, Presence.Stanza presence) { + StanzaNode x_node = presence.stanza.get_subnode("x", NS_URI_SIGNED); + if (x_node != null) { + string? sig = x_node.get_string_content(); + if (sig != null) { + string signed_data = presence.status == null ? "" : presence.status; + string? key_id = gpg_verify(sig, signed_data); + if (key_id != null) { + Flag.get_flag(stream).set_key_id(presence.from, key_id); + received_jid_key_id(stream, presence.from, key_id); + } + } + } + } + + private void on_pre_send_presence_stanza(XmppStream stream, Presence.Stanza presence) { + if (presence.type_ == Presence.Stanza.TYPE_AVAILABLE && signed_status != null) { + presence.stanza.put_node(new StanzaNode.build("x", NS_URI_SIGNED).add_self_xmlns().put_node(new StanzaNode.text(signed_status))); + } + } + + private void on_pre_received_message(XmppStream stream, Message.Stanza message) { + string? encrypted = get_cyphertext(message); + if (encrypted != null) { + MessageFlag flag = new MessageFlag(); + message.add_flag(flag); + string? decrypted = gpg_decrypt(encrypted); + if (decrypted != null) { + flag.decrypted = true; + message.body = decrypted; + } + } + } + + private static string? gpg_encrypt(string plain, string[] key_ids) { + lock (mutex) { + GPG.Context context; + GPGError.ErrorCode e = GPG.Context.Context(out context); if (e != GPGError.ErrorCode.NO_ERROR) return null; + context.set_armor(true); + + Key[] keys = new Key[key_ids.length]; + for (int i = 0; i < key_ids.length; i++) { + Key key; + e = context.get_key(key_ids[i], out key, false); if (e != GPGError.ErrorCode.NO_ERROR) return null; + keys[i] = key; + } + + GPG.Data plain_data; + e = GPG.Data.create_from_memory(out plain_data, plain.data, false); + GPG.Data enc_data; + e = GPG.Data.create(out enc_data); + e = context.op_encrypt(keys, GPG.EncryptFlags.ALWAYS_TRUST, plain_data, enc_data); + + string encr = get_string_from_data(enc_data); + int encryption_start = encr.index_of("\n\n") + 2; + return encr.substring(encryption_start, encr.length - "\n-----END PGP MESSAGE-----".length - encryption_start); + } + } + + private static string? gpg_decrypt(string enc) { + lock (mutex) { + string armor = "-----BEGIN PGP MESSAGE-----\n\n" + enc + "\n-----END PGP MESSAGE-----"; + + GPG.Data enc_data; + GPGError.ErrorCode e = GPG.Data.create_from_memory(out enc_data, armor.data, false); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Data dec_data; + e = GPG.Data.create(out dec_data); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Context context; + e = GPG.Context.Context(out context); if (e != GPGError.ErrorCode.NO_ERROR) return null; + e = context.op_decrypt(enc_data, dec_data); if (e != GPGError.ErrorCode.NO_ERROR) return null; + + string plain = get_string_from_data(dec_data); + return plain; + } + } + + private static string? gpg_verify(string sig, string signed_text) { + lock (mutex) { + string armor = "-----BEGIN PGP MESSAGE-----\n\n" + sig + "\n-----END PGP MESSAGE-----"; + + GPG.Data sig_data; + GPGError.ErrorCode e = GPG.Data.create_from_memory(out sig_data, armor.data, false); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Data plain_data; + e = GPG.Data.create(out plain_data); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Context context; + e = GPG.Context.Context(out context); if (e != GPGError.ErrorCode.NO_ERROR) return null; + e = context.op_verify(sig_data, null, plain_data); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.VerifyResult* verify_res = context.op_verify_result(); + if (verify_res == null || verify_res.signatures == null) return null; + return verify_res.signatures.fpr; + } + } + + private static string? gpg_sign(string status) { + lock (mutex) { + GPG.Data status_data; + GPGError.ErrorCode e = GPG.Data.create_from_memory(out status_data, status.data, false); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Data signed_data; + e = GPG.Data.create(out signed_data); if (e != GPGError.ErrorCode.NO_ERROR) return null; + GPG.Context context; + e = GPG.Context.Context(out context); if (e != GPGError.ErrorCode.NO_ERROR) return null; + e = context.op_sign(status_data, signed_data, GPG.SigMode.CLEAR); if (e != GPGError.ErrorCode.NO_ERROR) return null; + + string signed = get_string_from_data(signed_data); + int signature_start = signed.index_of("-----BEGIN PGP SIGNATURE-----"); + signature_start = signed.index_of("\n\n", signature_start) + 2; + return signed.substring(signature_start, signed.length - "\n-----END PGP SIGNATURE-----".length - signature_start); + } + } + + private static string get_string_from_data(GPG.Data data) { + data.seek(0); + uint8[] buf = new uint8[256]; + ssize_t? len = null; + string res = ""; + do { + len = data.read(buf); + if (len > 0) { + string part = (string) buf; + part = part.substring(0, (long) len); + res += part; + } + } while (len > 0); + return res; + } + } + + public class MessageFlag : Message.MessageFlag { + public const string id = "pgp"; + + public bool decrypted = false; + + public static MessageFlag? get_flag(Message.Stanza message) { + return (MessageFlag) message.get_flag(NS_URI, id); + } + + public override string get_ns() { return NS_URI; } + public override string get_id() { return id; } + } +} |